This invention relates to recovery of metals from solution. In particular it describes a novel process for reducing metal ions with hydrogen in a particulate bed-contactor.
Various methods, such as electrolysis and cementation, exist for recovering or precipitating metal values from ionic solution in various industries. Particular difficulty is encountered in recovering valuable metals from very dilute solutions. Plating or rinse solutions containing a few parts per million of palladium, gold, silver, or other metals are discarded without recovering the metals, resulting in monetary loss and environmental water pollution.